A mobile station may transmit a message to a base station by transmitting one or more access probes in an access channel. In many cases, the access channel is a shared channel that multiple mobile stations in the base station's wireless coverage area are able to use to transmit messages to the base station. Thus, it may be possible for two or more mobile stations to transmit access probes in the access channel at the same time. This may cause a “collision” between the mobile stations' access probes, which may result in the base station being unable to decode the access probes from either mobile station.